Fix ValueError with the default config file

Here's what used to happen after

    # apt-get install pov-server-page
    # pov-update-server-page -v
    Traceback (most recent call last):
      File "/usr/sbin/pov-update-server-page", line 387, in <module>
        main()
      File "/usr/sbin/pov-update-server-page", line 371, in main
        enabled = cp.getboolean('pov-server-page', 'enabled')
      File "/usr/lib/python2.7/ConfigParser.py", line 370, in getboolean
        raise ValueError, 'Not a boolean: %s' % v
    ValueError: Not a boolean: